This invention relates generally to methods and apparatus for the cleaning of connectors utilized in connecting optical fibers. The method and apparatus may be advantageously utilized to clean single fiber and multifibers connectors.
The use of optical fiber for transmitting information, such as data or voice communications, is increasing. Optical fiber offers advantages over traditional wire due, for example, to the improved transmission speed and larger information capacity for the same sized cable.
Connectors are used to terminate and couple one or more optical fibers to other optical fibers or to other terminals. These connectors typically are divided into classes depending on the number of optical fibers terminated within the connector. For example, classes include connectors for a single optical fiber, for two optical fibers, and for more than two optical fibers (usually in multiples of two). Connectors for two or more optical fibers, referred to herein as xe2x80x9cmultifiber connectors.xe2x80x9d are desirable since they allow simultaneous transmission and reception of information.
Such connectors include configurations that generally define the positioning of the one or more optical fibers within the connector, as well as the structure for securing the connector to other connectors or terminals. For example, a number of different types of connectors for a single optical fiber include SC, FC, ST(copyright), and D4 connectors. Similarly, a number of different types of connectors for two optical fibers include the MT, MTP, and MT-RJ connectors, as well as the UNICAM(copyright) and SC-DC(trademark) connectors produced by the assignee of the present invention.
Various types of the aforementioned connectors have been used to join optical fibers in a network communication system. Connection capabilities, however, can be significantly degraded by contamination of the connection interface by dirt, oil, or other foreign matter that interferes with the optical connection.
It is therefore advantageous to clean the polished end faces of optical connectors before the connection is made. Conventionally, the polished end face of an optical connector is wiped with a soft cloth or paper before the connection is made. Another method involves applying ethanol to the cleaning cloth or paper and then using a compressed gas, such as a fluorocarbon gas, to remove the remaining ethanol and dust from the cloth or paper from the connection surface.
U.S. Pat. No. 5,117,528, the disclosure of which is incorporated herein by reference, discloses an apparatus for cleaning the surface of optical connectors. In one embodiment disclosed in U.S. Pat. No. 5,117,528, a cleaning cloth is disposed on a roll inside of a mechanism that passes the cleaning cloth between a guide for receiving the housing of an optical connector disposed above the cleaning cloth and a lower plate against which the optical connector is pressed. The used cleaning cloth is stored on a take-up reel. In accordance with this embodiment disclosed in the patent, clean cloth is thereby made available for cleaning optical connectors.
The methods known in the prior art however, have dealt mainly with cleaning optical connectors in which the optical fiber is exposed at the end of the connector. Because the fiber is accessible, it is easily wiped off with a cloth. However, developments in multi-fiber communications systems have given rise to a number of multifiber connectors. Some of these multifiber connectors have one or more guide pins that serve to orient the connector so that the fibers are properly aligned. A number of connectors have multiple guide pins that extend beyond the surface of the optical fibers. For example, the MTP and the MT-RJ connectors, which are used extensively in fiber optic networks, have two guide pins that extend beyond the surface of the optical fibers making it difficult to adequately clean the surface of the optical fibers without bending or otherwise damaging the guide pins.
Due to the inadequacies of the present devices and methods for cleaning optical connectors with guide pins, there is a particular need for apparatus and methods that allow efficient and thorough cleaning of the surface of the optical fibers without damaging the guide pins extending from the optical connector. The invention disclosed herein provides an apparatus that overcomes the deficiencies of the prior art in this regard. The apparatus of the present invention also provides additional advantages described below.
The present invention provides cleaning apparatus advantageously well suited for the cleaning of optical fibers and optical fiber connectors. The apparatus may be utilized to clean the polished end faces of a ferrule mounted on the end of an optical fiber and the mating surfaces of a connector to minimize contamination of a connection interface between fibers or connectors by dirt, oil, or other foreign matter that interferes with the optical connection.
In one aspect, the present invention provides a device that may be utilized in a system for cleaning the polished end face of an optical connector. The device is particularly well suited for cleaning connectors having one or more guide pins. According to this aspect of the present invention, the device includes a plate for receiving an optical connector. The plate has a top surface with at least one rail disposed on the top surface. The rail extends upward from the surface and has a height above the surface sufficient to accommodate guide pins extending from an optical connector. An overlay is placed on the device and the optical connector placed into contact with the overlay such that any guide pins attached to the optical connector are received on either side of the rail beneath the overlay.
In a second aspect, the present invention provides a guide member having a surface with at least one opening for receiving the housing of an optical connector. The guide member may also have one or more rails extending downward from its lower surface. The guide member is disposed on top of the overlay such that the opening of the guide member is substantially centered around a rail disposed on the device.
A third aspect of the present invention provides a method for cleaning the polished end faces of an optical connector having one or more guide pins. The method includes the steps of contacting the optical connector to an overlay disposed on a device that includes a plate having a top surface with at least one rail disposed on the surface. The connector is placed into contact with the overlay such that any guide pins attached to the optical connector are received on either side of the rail beneath the overlay. The optical connector may then be moved along at least a portion of the rail thereby further cleaning the polished end faces of the fibers of the optical connector on the overlay.
A fourth aspect of the present invention provides a method for cleaning the polished end faces of fibers of an optical connector having one or more guide pins. The method includes placing the optical connector through a guide member formed to receive the housing of the optical connector and that is disposed on top of an overlay such that the opening of the guide is substantially centered around a rail on a plate below the overlay. The optical connector is then contacted to an overlay disposed on a device that includes a plate having a top surface with at least one rail disposed on the surface. The connector is placed into contact with the overlay such that any guide pins attached to the optical connector are received on either side of the rail beneath the overlay. The optical connector may then be moved along at least a portion of the rail thereby further cleaning the polished end face of the optical connector on the overlay.
In a fifth aspect, the present invention provides a device for cleaning the polished end face of an optical connector having one or more guide pins that may be used in an apparatus such as the one disclosed in U.S. Pat. No. 5,117,528. The device includes an insert for receiving an optical connector. The insert has a surface with a rail extending upward from the surface to a height sufficient to accommodate the guide pins of an optical connector. An overlay is then disposed on the insert.
In a sixth aspect, the present invention provides an apparatus that further includes a guide member having a surface with at least one opening for receiving an optical connector. The guide member may include a rail extending downward from the surface that may contact the overlay. The guide member is disposed on top of the overlay such that the opening of the guide member is substantially centered around the rail of the insert.
A seventh aspect of the present invention includes a method for cleaning the polished end faces of fibers of an optical connector that includes advancing a sheet of overlay disposed on a roll such that a segment of said overlay is located on a surface with at least one rail disposed on said surface. The rail has a height above the surface sufficient to accommodate guide pins extending from the optical connector. The optical connector is then contacted to the overlay. After contact, the optical connector may be removed from contact with the overlay. It is also contemplated that after the connector is contacted to the overlay, the connector may be moved along the rail while the optical connector is in contact with the overlay.
In an eighth aspect of the present invention, the optical connector is placed into a guide member with at least one opening for receiving said optical connector on top of said overlay. It is contemplated that the guide member will be disposed such that the opening of the guide member is substantially centered around the rail disposed on the insert below.
Additional objects, aspects and advantages of the invention will become apparent to those skilled in the art upon reference to the preferred embodiments and the included drawings.